﻿238 PROCEEDINGS OF THE NATIONAL MUSEUM vol. lOo 



translucent, white scales, which become darker on upper parts of 

 pronotal lobes and anterior pronotum. Pleural bristles : anterior pro- 

 notals four to six dark bristles above and a number of lighter hairs 

 and bristles below ; one dark posterior pronotal ; spiraculars three small 

 dark bristles ; propleurals four to six light hairs and bristles ; lower 

 sternopleurals a group of light hairs ; usually one light upper sterno- 

 pleural ; three to six dark prealars ; upper mesepimerals 10 to 12 light 

 hairs. Halteres light and bare on base and lower part of stem, upper 

 part of stem and knob dark-scaled. 



Wings: Scales all dark. Outstanding scales broad on all veins 

 dorsally, narrow on lower surface of veins 3 to 6. Bases of fork cells 

 equidistant from wing base, that of lower fork cell may be slightly 

 nearer. Fringe mostly dark. Squama fringed. 



Legs : All dark-scaled except for white-scaled coxae and trochanters ; 

 ventral surfaces of all femora and tibiae light-scaled. Fifth tarsal 

 segment of front leg modified; enlarged claw with tooth near apex; 

 that of middle leg unmodified, claws subequal, simple. Apex of hind 

 tibia and base of first hind tarsal segment with specialized hairs and 

 scales. Hind tibia 0.9 of middle tibia. 



Abdomen : Very dark, iridescent, bronzy dorsally ; lateral portions 

 of tergites light-scaled (invisible from aboA'e) ; ventral surface uni- 

 formly white-scaled. Bristles largely restricted to the first and ter- 

 minal segments. 



Genitalia (fig. 33, c) : Sidepiece conical, densely covered with scales 

 laterally and ventrally ; dorsal surface with bristles only; bristles pre- 

 sent on basal portion. Basal lobe with about 10 large bristles and 

 numerous smaller bristles and hairs. Clasper long, slender, smooth, 

 with a short terminal spine, Mesosome simple, slender ; composed of 

 two lateral sclerotized plates, each with two long dorsal projections and 

 a short apicoventral spur. Tenth sternite with a strong, single apical 

 tooth; basal arm expanded at base, abruptly narrowed at middle. 

 Ninth tergite (fig. 33, c) with a triangular median emargination, at 

 its widest point less than half as wide as the lobes; lobes wide and 

 short, each with about 14 flattened, expanded bristles with very fine 

 curved ends; bristles arranged in irregular double row on apex of 

 lobes, inner dorsal bristles usually very wide. 



Female. — Essentially as the male, except for sexual characters. 

 Terminal antennal segments not elongate, whorls very sparse. Pro- 

 boscis a little less than 1.1 of front femur, slightly shorter than abdo- 

 men. Palpi stout, 0.17 of proboscis, terminal segment with two to 

 four strong dark bristles arising on the apex, bristles widely spaced 

 at base. Usually six spiracular bristles and one postnotal. Claws sim- 

 ple and normal on all legs. 



Pupa. — ^Unknown. 



Larva. — Four third-instar larvae associated with the adults of this 



